According to Au7o's analysis of 65+ owner reports, the 2021 Peugeot 508 has 3 documented known issues, with 2 rated critical. The most serious are Diesel DPF Regeneration Issues ($300-$2,500 repair) and Plug-In Hybrid Traction Battery Overheats — Thermal Runaway and Fire Recall ($0-$0 repair). Across all issues with published estimates, repair costs range from $300 to $2,500. DIY maintenance guides at au7o.io.
On the 2011-2026 Peugeot 508, the 508 diesel suffers from DPF regeneration failures, particularly on first-generation models with the additive DPF system. Frequent short journeys prevent the regeneration cycle from completing, leading to progressive soot buildup.
Perform forced DPF regeneration via diagnostic tool. Top up the Eolys additive system. For severely blocked units, professional off-car DPF cleaning is recommended before resorting to replacement.
High Confidence65 owner reportsReviewed Invalid Date
On the 2018-2022 Peugeot 508, an engine control unit software defect on BlueHDi diesel 508s stops the malfunction indicator lamp being commanded on when the AdBlue urea injector fails. The SCR system stops dosing and NOx emissions rise above the legal limit, but the driver sees nothing on the dash until the car eventually enters the AdBlue start-prevention sequence or fails an emissions check. Stellantis campaign codes MF6 and MYC cover 556,699 vehicles built 6 December 2017 to 21 November 2022 across twelve Peugeot models including the 508, and address both the urea injector MIL defect (cars built 15 June 2020 onward) and an earlier SCR/DPF diagnostic failure (cars built 6 December 2017 to 7 November 2019). This is distinct from ordinary DPF regeneration trouble — here the diagnostic itself is disabled, so the usual early warning never appears. Petrol PureTech and Hybrid 508s are not affected.
Common Symptoms
AdBlue tank level barely drops between refills
No engine warning lamp despite a dead urea injector
Fails NOx emissions testing
Later AdBlue start-prevention countdown appears without prior warning
How to Fix
Check the VIN against campaigns MF6 and MYC at a Peugeot dealer; the remedy is a free ECU software update. Ask for an SCR system inspection at the same visit — an injector that has been dead for months without a lamp often leaves urea crystallisation in the injector and dosing line, and a fouled or drifting NOx sensor, none of which the reflash fixes. Track AdBlue consumption after the update: a tank that stops draining is the practical sign the injector is still not dosing.
On the 2019-2022 Peugeot 508 1.6 PureTech 180/200 PHEV, second-generation 508 plug-in hybrids built between 12 March 2019 and 8 December 2022 are subject to a serious EU recall (Stellantis campaign codes MEH and MEJ, RAPEX alerts 28/2023 and 30/2023, references A12/01619/23 and A12/01741/23, published July 2023) covering 43,798 vehicles worldwide together with the sister 3008 Hybrid4. The battery management software could fail to detect a developing overheat in the high-voltage traction battery, allowing thermal runaway and, in the worst case, smoke or fire during charging or while driving. The 508 PHEV battery has been the subject of several distinct actions in this period — a cell voltage mismatch on early 2019 production, this battery-monitoring software defect, and a separate campaign where the HV battery reinforcing plate or battery cover was not wax-coated, letting water in and corroding the battery enclosure. Petrol PureTech and BlueHDi diesel 508s are not affected; this is specific to the plug-in hybrid.
Common Symptoms
High-voltage system fault warning
Charging interrupts or refuses to start
Smoke or burning smell from under the car during or after charging
Reduced electric range or unavailable EV mode
How to Fix
Have the VIN checked by a Peugeot dealer against campaigns MEH and MEJ plus the separate battery-cover corrosion action — several 508 PHEVs qualify for more than one. Remedies are free and include a battery management software update and, where the protective wax coating is missing, inspection and treatment or replacement of the HV battery reinforcing plate and cover. Until the work is done, follow Stellantis's interim guidance and avoid leaving the car charging unattended indoors or in an attached garage. Any smell of hot electronics, smoke, unexplained charge interruption or an HV system fault message should be treated as an emergency: stop charging, park away from buildings and call Peugeot assistance.
According to Au7o's analysis of 65+ owner reports, the 2021 Peugeot 508 has 3 documented issues. The most frequently reported are: Diesel DPF Regeneration Issues, Plug-In Hybrid Traction Battery Overheats — Thermal Runaway and Fire Recall, BlueHDi AdBlue Injector Can Fail With No Dashboard Warning — Recall MF6 / MYC. Of these, 2 are rated critical and should be addressed promptly.
Is the Peugeot 508 reliable?
The 2021 Peugeot 508 has 3 known issues documented across 65+ owner reports. 2 issues are rated critical: Diesel DPF Regeneration Issues and Plug-In Hybrid Traction Battery Overheats — Thermal Runaway and Fire Recall. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Peugeot 508 problems?
Repair costs for known Peugeot 508 issues range from $0 to $2,500, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Diesel DPF Regeneration Issues, typically costs $300-$2,500 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2011-2026 Peugeot 508 Diesel DPF Regeneration Issues?
The 508 diesel suffers from DPF regeneration failures, particularly on first-generation models with the additive DPF system. Frequent short journeys prevent the regeneration cycle from completing, leading to progressive soot buildup. Repairs typically run $300-$2,500. Severity: high.
What is the 2019-2022 Peugeot 508 Plug-In Hybrid Traction Battery Overheats — Thermal Runaway and Fire Recall?
Second-generation 508 plug-in hybrids built between 12 March 2019 and 8 December 2022 are subject to a serious EU recall (Stellantis campaign codes MEH and MEJ, RAPEX alerts 28/2023 and 30/2023, references A12/01619/23 and A12/01741/23, published July 2023) covering 43,798 vehicl… Repairs typically run $0-$0. Severity: high.
What is the 2018-2022 Peugeot 508 BlueHDi AdBlue Injector Can Fail With No Dashboard Warning — Recall MF6 / MYC?
An engine control unit software defect on BlueHDi diesel 508s stops the malfunction indicator lamp being commanded on when the AdBlue urea injector fails. The SCR system stops dosing and NOx emissions rise above the legal limit, but the driver sees nothing on the dash until the c… Repairs typically run $0-$0. Severity: medium.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
